MAPT and early-onset autosomal dominant Alzheimer disease: In the context of reduced NA, the toxic inflammatory effect of Aβ and tau are heightened, exacerbating neurodegeneration.63 64 NA also regulates microglial surveillance and synaptotoxicity,6 where microglia activation is predictive of faster cognitive decline of people with Alzheimer’s disease and MCI.65 Therefore, noradrenergic treatments might have both symptomatic and disease-modifying effects.